cpufreq: intel_pstate: One set of global limits in active mode
In the active mode intel_pstate currently uses two sets of global
limits, each associated with one of the possible scaling_governor
settings in that mode: "powersave" or "performance".
The driver switches over from one of those sets to the other
depending on the scaling_governor setting for the last CPU whose
per-policy cpufreq interface in sysfs was last used to change
parameters exposed in there. That obviously leads to no end of
issues when the scaling_governor settings differ between CPUs.
The most recent issue was introduced by commit a240c4aa5d0f (cpufreq:
intel_pstate: Do not reinit performance limits in ->setpolicy)
that eliminated the reinitialization of "performance" limits in
intel_pstate_set_policy() preventing the max limit from being set
to anything below 100, among other things.
Namely, an undesirable side effect of commit a240c4aa5d0f is that
now, after setting scaling_governor to "performance" in the active
mode, the per-policy limits for the CPU in question go to the highest
level and stay there even when it is switched back to "powersave"
later.
As it turns out, some distributions set scaling_governor to
"performance" temporarily for all CPUs to speed-up system
initialization, so that change causes them to misbehave later.
To fix that, get rid of the performance/powersave global limits
split and use just one set of global limits for everything.
From the user's persepctive, after this modification, when
scaling_governor is switched from "performance" to "powersave"
or the other way around on one CPU, the limits settings (ie. the
global max/min_perf_pct and per-policy scaling_max/min_freq for
any CPUs) will not change. Still, switching from "performance"
to "powersave" or the other way around changes the way in which
P-states are selected and in particular "performance" causes the
driver to always request the highest P-state it is allowed to ask
for for the given CPU.
Fixes: a240c4aa5d0f (cpufreq: intel_pstate: Do not reinit performance limits in ->setpolicy)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 08e134f..7b07803 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -364,9 +364,7 @@
static bool acpi_ppc;
#endif
-static struct perf_limits performance_limits;
-static struct perf_limits powersave_limits;
-static struct perf_limits *limits;
+static struct perf_limits global;
static void intel_pstate_init_limits(struct perf_limits *limits)
{
@@ -377,14 +375,6 @@
limits->max_sysfs_pct = 100;
}
-static void intel_pstate_set_performance_limits(struct perf_limits *limits)
-{
- intel_pstate_init_limits(limits);
- limits->min_perf_pct = 100;
- limits->min_perf = int_ext_tofp(1);
- limits->min_sysfs_pct = 100;
-}
-
static DEFINE_MUTEX(intel_pstate_driver_lock);
static DEFINE_MUTEX(intel_pstate_limits_lock);
@@ -507,7 +497,7 @@
* correct max turbo frequency based on the turbo state.
* Also need to convert to MHz as _PSS freq is in MHz.
*/
- if (!limits->turbo_disabled)
+ if (!global.turbo_disabled)
cpu->acpi_perf_data.states[0].core_frequency =
policy->cpuinfo.max_freq / 1000;
cpu->valid_pss_table = true;
@@ -626,7 +616,7 @@
cpu = all_cpu_data[0];
rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
- limits->turbo_disabled =
+ global.turbo_disabled =
(misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
}
@@ -851,7 +841,7 @@
static void intel_pstate_hwp_set(struct cpufreq_policy *policy)
{
int min, hw_min, max, hw_max, cpu;
- struct perf_limits *perf_limits = limits;
+ struct perf_limits *perf_limits = &global;
u64 value, cap;
for_each_cpu(cpu, policy->cpus) {
@@ -863,19 +853,22 @@
rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap);
hw_min = HWP_LOWEST_PERF(cap);
- if (limits->no_turbo)
+ if (global.no_turbo)
hw_max = HWP_GUARANTEED_PERF(cap);
else
hw_max = HWP_HIGHEST_PERF(cap);
- min = fp_ext_toint(hw_max * perf_limits->min_perf);
+ max = fp_ext_toint(hw_max * perf_limits->max_perf);
+ if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE)
+ min = max;
+ else
+ min = fp_ext_toint(hw_max * perf_limits->min_perf);
rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
value &= ~HWP_MIN_PERF(~0L);
value |= HWP_MIN_PERF(min);
- max = fp_ext_toint(hw_max * perf_limits->max_perf);
value &= ~HWP_MAX_PERF(~0L);
value |= HWP_MAX_PERF(max);
@@ -968,20 +961,11 @@
}
static void intel_pstate_update_policies(void)
- __releases(&intel_pstate_limits_lock)
- __acquires(&intel_pstate_limits_lock)
{
- struct perf_limits *saved_limits = limits;
int cpu;
- mutex_unlock(&intel_pstate_limits_lock);
-
for_each_possible_cpu(cpu)
cpufreq_update_policy(cpu);
-
- mutex_lock(&intel_pstate_limits_lock);
-
- limits = saved_limits;
}
/************************** debugfs begin ************************/
@@ -1060,7 +1044,7 @@
static ssize_t show_##file_name \
(struct kobject *kobj, struct attribute *attr, char *buf) \
{ \
- return sprintf(buf, "%u\n", limits->object); \
+ return sprintf(buf, "%u\n", global.object); \
}
static ssize_t intel_pstate_show_status(char *buf);
@@ -1151,10 +1135,10 @@
}
update_turbo_state();
- if (limits->turbo_disabled)
- ret = sprintf(buf, "%u\n", limits->turbo_disabled);
+ if (global.turbo_disabled)
+ ret = sprintf(buf, "%u\n", global.turbo_disabled);
else
- ret = sprintf(buf, "%u\n", limits->no_turbo);
+ ret = sprintf(buf, "%u\n", global.no_turbo);
mutex_unlock(&intel_pstate_driver_lock);
@@ -1181,19 +1165,19 @@
mutex_lock(&intel_pstate_limits_lock);
update_turbo_state();
- if (limits->turbo_disabled) {
+ if (global.turbo_disabled) {
pr_warn("Turbo disabled by BIOS or unavailable on processor\n");
mutex_unlock(&intel_pstate_limits_lock);
mutex_unlock(&intel_pstate_driver_lock);
return -EPERM;
}
- limits->no_turbo = clamp_t(int, input, 0, 1);
-
- intel_pstate_update_policies();
+ global.no_turbo = clamp_t(int, input, 0, 1);
mutex_unlock(&intel_pstate_limits_lock);
+ intel_pstate_update_policies();
+
mutex_unlock(&intel_pstate_driver_lock);
return count;
@@ -1218,19 +1202,16 @@
mutex_lock(&intel_pstate_limits_lock);
- limits->max_sysfs_pct = clamp_t(int, input, 0 , 100);
- limits->max_perf_pct = min(limits->max_policy_pct,
- limits->max_sysfs_pct);
- limits->max_perf_pct = max(limits->min_policy_pct,
- limits->max_perf_pct);
- limits->max_perf_pct = max(limits->min_perf_pct,
- limits->max_perf_pct);
- limits->max_perf = percent_ext_fp(limits->max_perf_pct);
-
- intel_pstate_update_policies();
+ global.max_sysfs_pct = clamp_t(int, input, 0 , 100);
+ global.max_perf_pct = min(global.max_policy_pct, global.max_sysfs_pct);
+ global.max_perf_pct = max(global.min_policy_pct, global.max_perf_pct);
+ global.max_perf_pct = max(global.min_perf_pct, global.max_perf_pct);
+ global.max_perf = percent_ext_fp(global.max_perf_pct);
mutex_unlock(&intel_pstate_limits_lock);
+ intel_pstate_update_policies();
+
mutex_unlock(&intel_pstate_driver_lock);
return count;
@@ -1255,19 +1236,16 @@
mutex_lock(&intel_pstate_limits_lock);
- limits->min_sysfs_pct = clamp_t(int, input, 0 , 100);
- limits->min_perf_pct = max(limits->min_policy_pct,
- limits->min_sysfs_pct);
- limits->min_perf_pct = min(limits->max_policy_pct,
- limits->min_perf_pct);
- limits->min_perf_pct = min(limits->max_perf_pct,
- limits->min_perf_pct);
- limits->min_perf = percent_ext_fp(limits->min_perf_pct);
-
- intel_pstate_update_policies();
+ global.min_sysfs_pct = clamp_t(int, input, 0 , 100);
+ global.min_perf_pct = max(global.min_policy_pct, global.min_sysfs_pct);
+ global.min_perf_pct = min(global.max_policy_pct, global.min_perf_pct);
+ global.min_perf_pct = min(global.max_perf_pct, global.min_perf_pct);
+ global.min_perf = percent_ext_fp(global.min_perf_pct);
mutex_unlock(&intel_pstate_limits_lock);
+ intel_pstate_update_policies();
+
mutex_unlock(&intel_pstate_driver_lock);
return count;
@@ -1387,7 +1365,7 @@
u32 vid;
val = (u64)pstate << 8;
- if (limits->no_turbo && !limits->turbo_disabled)
+ if (global.no_turbo && !global.turbo_disabled)
val |= (u64)1 << 32;
vid_fp = cpudata->vid.min + mul_fp(
@@ -1557,7 +1535,7 @@
u64 val;
val = (u64)pstate << 8;
- if (limits->no_turbo && !limits->turbo_disabled)
+ if (global.no_turbo && !global.turbo_disabled)
val |= (u64)1 << 32;
return val;
@@ -1683,9 +1661,9 @@
int max_perf = cpu->pstate.turbo_pstate;
int max_perf_adj;
int min_perf;
- struct perf_limits *perf_limits = limits;
+ struct perf_limits *perf_limits = &global;
- if (limits->no_turbo || limits->turbo_disabled)
+ if (global.no_turbo || global.turbo_disabled)
max_perf = cpu->pstate.max_pstate;
if (per_cpu_limits)
@@ -1820,7 +1798,7 @@
sample->busy_scaled = busy_frac * 100;
- target = limits->no_turbo || limits->turbo_disabled ?
+ target = global.no_turbo || global.turbo_disabled ?
cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;
target += target >> 2;
target = mul_fp(target, busy_frac);
@@ -2116,7 +2094,7 @@
static int intel_pstate_set_policy(struct cpufreq_policy *policy)
{
struct cpudata *cpu;
- struct perf_limits *perf_limits = NULL;
+ struct perf_limits *perf_limits = &global;
if (!policy->cpuinfo.max_freq)
return -ENODEV;
@@ -2139,21 +2117,6 @@
mutex_lock(&intel_pstate_limits_lock);
- if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
- pr_debug("set performance\n");
- if (!perf_limits) {
- limits = &performance_limits;
- perf_limits = limits;
- }
- } else {
- pr_debug("set powersave\n");
- if (!perf_limits) {
- limits = &powersave_limits;
- perf_limits = limits;
- }
-
- }
-
intel_pstate_update_perf_limits(policy, perf_limits);
if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE) {
@@ -2177,16 +2140,9 @@
static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
{
struct cpudata *cpu = all_cpu_data[policy->cpu];
- struct perf_limits *perf_limits;
-
- if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
- perf_limits = &performance_limits;
- else
- perf_limits = &powersave_limits;
update_turbo_state();
- policy->cpuinfo.max_freq = perf_limits->turbo_disabled ||
- perf_limits->no_turbo ?
+ policy->cpuinfo.max_freq = global.turbo_disabled || global.no_turbo ?
cpu->pstate.max_freq :
cpu->pstate.turbo_freq;
@@ -2201,9 +2157,9 @@
unsigned int max_freq, min_freq;
max_freq = policy->cpuinfo.max_freq *
- perf_limits->max_sysfs_pct / 100;
+ global.max_sysfs_pct / 100;
min_freq = policy->cpuinfo.max_freq *
- perf_limits->min_sysfs_pct / 100;
+ global.min_sysfs_pct / 100;
cpufreq_verify_within_limits(policy, min_freq, max_freq);
}
@@ -2255,7 +2211,7 @@
/* cpuinfo and default policy values */
policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
update_turbo_state();
- policy->cpuinfo.max_freq = limits->turbo_disabled ?
+ policy->cpuinfo.max_freq = global.turbo_disabled ?
cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;
policy->cpuinfo.max_freq *= cpu->pstate.scaling;
@@ -2275,7 +2231,7 @@
return ret;
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
- if (limits->min_perf_pct == 100 && limits->max_perf_pct == 100)
+ if (IS_ENABLED(CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE))
policy->policy = CPUFREQ_POLICY_PERFORMANCE;
else
policy->policy = CPUFREQ_POLICY_POWERSAVE;
@@ -2301,7 +2257,7 @@
struct cpudata *cpu = all_cpu_data[policy->cpu];
update_turbo_state();
- policy->cpuinfo.max_freq = limits->turbo_disabled ?
+ policy->cpuinfo.max_freq = global.turbo_disabled ?
cpu->pstate.max_freq : cpu->pstate.turbo_freq;
cpufreq_verify_within_cpu_limits(policy);
@@ -2317,7 +2273,7 @@
update_turbo_state();
- max_freq = limits->no_turbo || limits->turbo_disabled ?
+ max_freq = global.no_turbo || global.turbo_disabled ?
cpu->pstate.max_freq : cpu->pstate.turbo_freq;
policy->cpuinfo.max_freq = max_freq;
if (policy->max > max_freq)
@@ -2425,13 +2381,7 @@
{
int ret;
- intel_pstate_init_limits(&powersave_limits);
- intel_pstate_set_performance_limits(&performance_limits);
- if (IS_ENABLED(CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE) &&
- intel_pstate_driver == &intel_pstate)
- limits = &performance_limits;
- else
- limits = &powersave_limits;
+ intel_pstate_init_limits(&global);
ret = cpufreq_register_driver(intel_pstate_driver);
if (ret) {